Selection and application of silicone release agent (IV)


IV. Application in Metal Casting and Machining


Silicone release agent has good thermal stability and decomposition at high temperature, so it is widely used in various metal casting.


The use of emulsion or solution release agent can be used to spray the mold release agent on the shell mold made of sand and phenolic resin and heated to 250 degrees Celsius, and then put into the heating furnace for several minutes. The mold release agent can also be sprayed on the wooden mold and then used to make the shell mold. Because of the use of demoulding agent, it is very easy to demould wood and metal molds, and the shell mold can be obtained without further processing. Therefore, precision castings can also be obtained in precision casting of low melting point metals such as zinc, lead and their alloys. The silicone oil demoulding agent with high temperature resistance can play a good role, and the concentration of demoulding agent used can also be used in precision casting of low melting point metals such as zinc, lead and their alloys. With a mass fraction of 1%~5%, it can achieve the purpose of low cost and good effect. For the new die used for the first time, it must be treated by high temperature or solvent, alkali solution or grinding treatment to remove the organic matter and oxide attached to the surface of the shell die. Then it can be put into use with high concentration of silicone oil emulsion or silicon paste solution. When storing the shell mould, the surface of the shell mould should also be protected by coating with silicone oil.


Commonly used die casting agents for aluminum alloy die casting are usually made up of modified silicone oil emulsion, wax emulsion, synthetic grease emulsion and so on. The release product of the mold release agent is 10~40%, and the end users need to dilute the release agent emulsion to the solid content 0.15~0.30% to use. Specific formula can be obtained by contact with the public number backstage communication.


V. Food demoulding agent and non-stick anti-stick paint for cooking utensils


Using the physiological inertia and excellent demoulding property of silicone resin, it is coated on the food baking tray or mould, and cured by heating to form a heat-resistant and strong anti-sticky film, which makes bread, snacks, candy and chocolate easy to demould. It not only saves vegetable oil, eliminates oil fume, but also improves the working environment and labor intensity. And the product has a glossy appearance. The stripping coating can be used dozens or hundreds of times continuously. The baking tray and the mould are always clean. When the coating fails, the appliances can be boiled in hot alkali solution for 10-30 minutes. The residual coating can be completely peeled off. After washing, alcohol washing and drying, the stripping agent can be re-coated and reused.


Various non-sticky cooking utensils, such as cookers, rice cookers, pancake pans, baking ovens, oil-free pancakes and egg pancakes, have entered tens of millions of households. Currently, fluorine resin is mainly used as anti-stick coating. Recently, the use of silicone resin demoulding anti-stick coating has developed rapidly. Silicone resin demoulding agent has the characteristics of room temperature drying and low temperature firing. The heat resistance is as high as 250 C, in case of overheating, it will not crack toxic substances, and the silicone resin has good adhesion to iron, aluminum and other metals. It can be directly coated on untreated and non-primer substrates with appropriate tackifiers, and the firing temperature is much lower than that of fluorine resin.


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